Flow based determination of Cr(VI) by adsorptive cathodic stripping voltammetry on an immobilized magnetic poly(ionic liquid) modified electrode

Abstract

In this work an electrochemical procedure for Cr(VI) flow based determination in tap water is presented. An AdCSV method was developed using a screen printed electrode modified with magnetic poly(1-allyl-3-methylimidazolium) chloride and the procedure does not require the addition of complexing agents in the solution unlike the methodologies reported so far for Cr(VI) determination. The flow based system is described and the control variables were studied in detail and optimized using a Taguchi parameters design. Under optimal conditions, the electrochemical sensor offered an excellent response to Cr(VI) and the limit of detection estimated from 3σ was 0.5 µg L (n = 3) allowing the analysis of tap water samples. The effect of interfering ions was also investigated below the maximum permissible limits for tap water according to Mexican standards. The presence of the magnetic particles on the sorbent allowed its easy modification on the electrode surface between each determination when removing the magnetic field placed in the wall-jet cell. Finally, the precision of the method was tested with tap water samples using standard addition method for Cr(VI) quantification and the accuracy was evaluated comparing the results with the dyphenylcarbazide method and by analyzing a certified water sample. The method shows good repeatability and reproducibility (%RSD less than 5%) making it feasible for Cr(VI) flow based determination and no significant difference is observed in the results obtained by both methods.

Poly(ionic liquid)-Assisted Synthesis of Open-Ended Carbon Nitride Tube for Efficient Photocatalytic Hydrogen Evolution under Visible-Light Irradiation

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“…Poly­(ionic liquid)­s, as a new kind of polymers, are obtained through the polymerization of ionic liquid monomers. Poly­(ionic liquid)­s not only possess the unique properties of an ionic liquid, such as low vapor pressure, high chemical and thermal stability, but also combine with the polymer properties, including multifunctionality, multivalency as well as processability. − The high polarity, good solubility, and self-assembly behavior endow the poly­(ionic liquid)­s as additives in catalysis, electrochemical devices, and any other fields. − Especially, they can be taken as the efficient solvent for the preparation of novel structured nanomaterials. Gao et al synthesized a series of bismuth sulfides with different morphologies by using poly­(ionic liquid)­s as additives.…”

Recent Advances in Electrochemical Monitoring of Chromium

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Flow-based System: A Highly Efficient Tool Speeds Up Data Production and Improves Analytical Performance

“…Based on the high sensitivity of stripping voltammetry, thus, this technique is famous for the determination of metals at low levels. [168][169][170][171] The design of a flow diagram is created for single and simultaneous detection based on the objective. The common working electrode material used are modified electrode with nanomaterials and polymers.…”